Recently, the use of yeast and its derivatives has become very popular in cosmetic applications. This is driven by the fact that yeast, being eukaryotic, has similar cellular biological processes to human cells and is known to trigger the production of beneficial proteins under stress. There is also considerable historical evidence for the use of yeast derivatives and their benefits in topical skin applications by the increase in oxygen uptake. For example, U.S. Pat. No. 4,540,571 discloses yeast derivatives that improve cutaneous respiration. Yeast cell derivatives are also reported to stimulate the production of collagen and elastin in skin cells.
Recent studies suggest that yeast cell extracts have the ability to promote ‘growth factors’ that stimulates wound healing. For example, U.S. Pat. No. 7,217,417 discloses a method that incorporates yeast cell derivatives into a gel-based formulation for wound healing.
For topical applications, the most commonly used yeast is Saccharomyces cerevisiae, also known as baker's yeast. Saccharomyces is categorized by the FDA as a “Generally Recognized as Safe (GRAS)” micro-organism. However, products containing Saccharomyces cerevisiae or its derivates normally have strong color and characteristic odor. Therefore, there is a need in the cosmetic industry for yeast and yeast extracts that provide beneficial effects to skin's, as well as desirable aesthetic values at the same time.
Resveratrol (3,4,5-transhydroxystilbene), a polyphenol found in several plants, has been of considerable interest due to its possible health benefits for treatment of cardiovascular disease, diabetes and cancer. Resveratrol is well known for its presence in red wine and can be extracted from grape skin. Resveratrol can also be found in good abundance in the leaves of various plants such as, for example, Japanese Knotweed (Polygonum cuspidatum). Resveratrol is considered to be related to a family of biologically active molecules isolated from plants that are routinely called or referred to as polyphenols. Polyphenols are a group of chemical substances found in plants, characterized by the presence of more than one phenol unit or building block per molecule. Polyphenols include, for example, flavonoids or isoflavonoids, catechins, anthrocyanins and proanthrocyanins.
Several studies in wide range of species have demonstrated the ability of resveratrol to positively affect cellular function and longevity. It is suggested that resveratrol affects cellular longevity by mimicking caloric restriction without requiring any reduction in calorie intake. This is accomplished by the activation of specific proteins, mainly belonging to the “Sirtuins” family of proteins as disclosed by Borra T. M. et. al. in J. Biol. Chem. 280, (2005) 17187.
In addition to caloric restriction, resveratrol is also being evaluated for its potential health benefits including triggering DNA-repair mechanisms, anti-carcinogenic and anti-oxidant properties.
Ciolino H. P. et al. discloses that resveratrol may be used to reverse the aging process due to cellular DNA damage. Mol Pharm 56 (1999) 4, 760. In addition, resveratrol has been found to inhibit the activity of several inflammatory enzymes in vitro, including cyclooxygenases and lipoxygenases. Pinto M. D., et al. “Resveratrol is a potent inhibitor of the dioxygenase activity of lipoxygenase.” J Agic Food Chem. 47(12), 4842-4846 (1999).
Resveratrol has demonstrated advantages in topical and oral applications, but it suffers from inherent chemical instability and has been shown to be somewhat cytotoxic to skin cells in its native form. It is also quite water-insoluble which makes formulating skin and hair care products with the molecule difficult. A need remains to develop novel ingredients based on resveratrol that are more beneficial and less difficult to work with. As such, it is appreciated that there is a need for an ingredient that provides combined advantages effects of resveratrol and the metabolic pathways of yeast, for use in personal care compositions.